Cops say Mireya Alejandra Lopez, 22, told authorities she drowned her twin sons. (Maricopa County Sheriff's Office)

Authorities in Arizona say they've arrested a woman who confessed to drowning her twin 2-year-old sons in a bathtub Sunday.

Avondale Police Sgt. Brandon Busse told KSAZ that Mireya Alejandra Lopez, 22, admitted to killing the boys and said she attempted to drown another family member, but was stopped by a relative. 

Police say Lopez is facing two counts of homicide and one count of attempted homicide. The third child, who was not identified by authorities, was not harmed. The identity of the twin victims was not immediately released. 

Emergency personnel were called to the home at approximately 12:30 p.m. local time Sunday. Busse told the Arizona Republic a family member called 911 after the twins were discovered in the bathtub. The sergeant said that by the time police arrived, the boys were on a bed and unresponsive. They were taken to separate local hospitals, where they were pronounced dead.

Avondale is a suburb of Phoenix, with a population of approximately 78,000 people. Neighbors told the Republic the home where the drownings took place is located in a quiet section of town.